Spectroscopic study of interfaces in Al/Ni periodic multilayers

TL;DR

This study uses electron-induced X-ray emission spectroscopy to analyze the chemical states at Al/Ni interfaces in multilayers, revealing the dominant intermetallic phase after annealing at 115°C.

Contribution

It demonstrates that XES can effectively characterize interface chemistry in multilayers, complementing X-ray diffraction methods.

Findings

Al3Ni is the main intermetallic phase at 115°C

XES provides detailed valence state information

Multilayer chemistry differs from pure metals and other intermetallics

Abstract

Using electron-induced X-ray emission spectroscopy (XES), we have studied two Al/Ni periodic multilayers that differ only by their annealing temperature: as-deposited and annealed at 115C. Our aim is to show that XES can provide further details about the chemistry at the metal-metal interface, in addition to what is obtained by X-ray diffraction. The distribution of valence states exhibiting Al 3p and Ni 3d character is determined from the analysis of the Al Kbeta and Ni Lalpha emission bands respectively. The multilayer emission bands are compared to those of reference materials: pure Al and Ni metals as well as Al3Ni, Al3Ni2 and AlNi intermetallics. We provide evidence that, for temperatures up to 115C, Al3Ni is the major component of the multilayer.